Switchable electric percolator

The percolator (1) has a passage tube (3) for a fluid, and electrical heaters (5a, 5b) attached to the tube and arranged within separate electric circuits (9a, 9b). A switch acting as a programmable actuator (11) that supplies the heaters with heating current, during operation, in a change-over cycle. Heat storage-reinforcement elements (7a, 7b) are attached between the heaters and a fluid-contacted inner surface of the tube. The actuator is formed such that the cycle is shorter than time required for heat transmission from a heat emitting surface of the heaters to the fluid in the tube. Independent claims are also included for the following: (1) a coffee-fully automatic machine including a supply voltage switching device (2) a method for heating a fluid by an electric percolator.